Solar PV system maintenance in accordance with the IEC 62446-1 standard

Solar PV system maintenance in accordance with the IEC 62446-1 standard

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Solar PV system maintenance in accordance with the IEC 62446-1 standard


Proper maintenance is required for the safe and reliable operation of long-term solar power generation systems, so performing electrical testing on the system in accordance with international standard is important. This article discusses the DC side testing of the IEC 62446-1 standard.
About IEC 62446-1
The IEC 62446-1 is an international standard for testing, documenting, and maintaining grid-connected photovoltaic systems. It sets standards for how system designers and installers of grid-connected PV systems must provide information and documentation to customers. This standard also describes DC testing of the PV system which can be used for periodic testing of the system.
In the standard, the test is classified into categories 1 and 2 according to the size of the PV system. Category 1 refers to all solar PV generation systems, whereas Category 2 refers to larger or more complicated systems such as mega solar power plants.

 
Small-scale PV power generation system
Mega-solar power plant
 
Category 1 Inspection
 
Inspection items
Earth protective continuity test and/or equipotential bonding conductor
Description
If the DC side has earthing, such as a frame or equipotential bonding, a continuity test is required.
Measuring Instruments
 
Polarity inspection
Check the polarity of the cables before connecting them to the switching device or inverter.
 
Combiner box test
A test to verify that all strings are connected correctly.
 
Strings open circuit voltage test
For checking the voltage of PV modules connected in series.
 
String circuit current test (short circuit or operational)
To confirm the function of strings and that there are no major issues
 
Functional test
Check the operation and installation of control devices such as relay switches and circuit breakers.
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Insulation resistance test
Test the insulation resistance to ensure electrical safety.
 
All Category 1 tests must be completed and passed before moving on to the additional Category 2 tests.
Category 2 Inspection
 
Inspection items
I-V curve test
Description
This test evaluates the current-voltage characteristics of PV strings.
Measuring Instruments
  • I-V curve tracer
 
 
Infrared thermographic inspection
The heat generation of PV modules is inspected by the IR thermal camera. By knowing the deviation of the temperature, problems like the bypass diode in the PV arrays can be detected.
  • Infrared Thermal Camera
 
 
Additional inspections are also available for inspections outside Category 1 and Category 2.
Additional test
 
Inspection items
Voltage to Ground-Resistive Ground System
Description
Measure the resistivity according to the technical documentation provided by PV module manufacturer.
Measuring Instruments
  • Loop Impedance Meter
 
 
Blocking diode test
This is required for the system using a blocking diode. Check for diode connections and signs of overheating.
 
Wet insulation test
To validate that the PV modules are safe when exposed to rain or dew, an insulation resistance test is done with the PV modules in a wet state.
 
 
Shade evaluation
This is to record the effect of shading by obstacles.
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Conclusion
Using the right measuring tools is important for keeping the system running and making sure it is safe. At HIOKI, we offer a variety of measuring instruments to ensure the safety and efficiency of measurements for our users.
 
 

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